Lunchbox and food-warmer assemblies



D. J. SHEPPARD LUNCHB OX AND FOOD-WARMER ASSEMBLIES May 5, 1970 4 Sheets-Sheet 1 Filed May 9, 1968 INVENTOR. DARREL J. SHEPPARD ATTORNEYS.

y 1970 D. J. SHEPPARD 3,509,870

LUNCHBOX AND FOOD-WARMER ASSEMBLIES Filed May 9, 1968 4 Sheets-Sheet 2 INVENTOR. DARREL J. SHEPPARD BY ATTO NEYS.

May 5, 1970 D. J. SHEPPARD LUNCHBOX AND FOOD-WARMER ASSEMBLIES 4 Sheets-Sheet 3 Filed May 9, 1968 |NVENTOR. DARREL J. SH EPPARD ATTOR EYS,

May 5, 1970 D. J. SHEPPARD 3,509,870

LUNCHBOX AND FOOD-WARMER ASSEMBLIES Filed May 9, 1968 4 Sheets-Sheet 4 F l G. 8 //4 INVENTOR. DARREL J. SHEPPARD WMZ4M 6 ATTORNEY United States Patent 3,509,870 LUNCHBOX AND FOOD-WARMER ASSEMBLIES Darrel J. Sheppard, Southfield, Mich., assignor of fifty percent to Willard A. Brooks, Royal Oak, Mich. Filed May 9, 1968, Ser. No. 727,943 Int. Cl. F24c 3/14 US. Cl. 126-265 Claims ABSTRACT OF THE DISCLOSURE A portable food warmer assembly adapted for storage in a lunchbox comprising a lidded container and an integral base compartment for the food warmer assembly, which comprises a base unit carrying a gas fuel tank spaced from the base unit side walls. An oven structure is carried by the base unit and has side walls selectively telescopically extensible into and out of the space intermediate the base unit side walls and the fuel tank. A burner tube connected with the fuel tank overlies same.

A manually operated valve is adapted to selectively admit fuel from the fuel tank to the burner tube. A lighter device similar to a flint-type cigarette lighter is adapted to be extended from the base unit for selective manual ignition of the fuel in the burner. A filler valve is provided on the tank. The valves and the lighter are accessible through apertures provided in the base unit side walls, which apertures are closed by the side walls of the oven structure When same are telescoped into the space provided.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to lunchbox structures and to portable food-warmers, in which the lunchbox provides a storage compartment for the portable food-warmer, which is substantially self-contained and includes an oven compartment in which the food which is otherwise stored in the lunchbox may be selectively warmed.

Background of the invention This invention arises as a result of a need for a device which will permit an individual to prepare a hot meal, particularly when away from home and other sources of such meals are inconvenient or nonexistent.

SUMMARY OF THE INVENTION The invention resides in the unique collapsible structure of the food-warmer assembly adapting same for convenient storage in the specially prepared compartment of a lunchbox, the food-warmer being self-contained with its own fuel tank, burner, valves and fuel igniting device being accessible for use when an oven portion is telescopically extended from the food-warmer unit.

DESCRIPTION OF THE PRIOR ART The following patents showing various lunchboxes and food-warmers are known to applicant:

U.S. Pats. Nos. 2,513,218, 2,518,343, 2,713,111, and 2,973,756. These patents disclose lunchbox constructions and food-warmers associated therewith, but it is apparent that they do not have the convenience and versatility of my invention.

DESCRIPTION OF THE DRAWINGS For a more complete understanding of my invention, reference may be had to the accompanying drawings, illustrating a preferred embodiment of the invention in which like reference characters refer to like parts throughout the several views, and in which:

FIG. 1 is a perspective view of a lunchbox showing the integral compartment in which the food-warmer assembly is adapted to be contained.

FIG. 2 is a perspective view, partially broken away, of the food-warmer assembly in collapsed or telescopically closed position but with the lid opened to show the interior, and with operable components deleted for clarity.

FIG. 3 is a cross-sectional view of the food-warmer assembly with the side walls of the oven in the extended position.

FIG. 4 is a cross-sectional view of the food-warmer assembly showing the side walls of the oven in collapsed position.

FIG. 5 is a top plan view of the food-warmer assembly with the lid open to illustrate some of the interior structure and components.

FIG. 6 is a perspective view of the fuel tank portion of the food-warmer assembly showing the valve, burner and lighting devices therefor.

FIG. 7 is an enlarged fragmentary cross-sectional view showing the lighting or igniting device of the present invention.

FIG. 8 is an enlarged fragmentary cross-sectional view of the device of FIG. 7 in operative position, and

FIG. 9 is an enlarged fragmentary cross-sectional view taken substantially on the line 9-9 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT The preferred embodiment of the present invention comprises a food-warmer unit 34, having a base unit 46 and an oven unit 50 either secured within or removably disposed within the base unit 46. The complete unit 34 can be readily stored in a food-warmer storage compartment '12 integrally formed with the bottom of a lunchbox container '10.

As illustrated in FIG. 1 the lunchbox 10 is substantially of any well known construction except that it is constructed to be adaptable to the present invention.

The base portion 16 of the lunchbox 10 has side walls 24 and a bottom wall 25. The bottom wall 25 is secured to and integral with a top wall 26 of a storage compartment 12 for receiving the portable food-warmer unit 34. The food-warmer storage compartment 12 preferably comprises the top wall 26, side walls 28, bottom wall 30 and an open side 32. This storage compartment 12 selectively slidingly receives and stores the foodwarmer unit generally indicated at 34.

As shown in FIGS. 2, 3 and 4, the food-warmer unit 34 preferably comprises the aforesaid base unit 46, vertically telescopically extensible side walls 38 and an oven unit 50. The base unit 46 has side walls 44, a bottom wall 48 integral therewith and an open top. The extensible side walls 38 are disposed within the base unit 46 between the outer walls 44 and the oven unit 50 and are selectively telescopically extensible into and out of this space. On the outermost extensible side wall 38 a lid or top plate 36 is hingedly secured thereto as at 40 and 42.

The oven unit 50 has upstanding side walls 52, a base wall 53 and an open top. The base Wall 53 may or may not be secured to the bottom wall 48 of the base unit 46 as desired.

A reflector plate 54 is emplaced with the oven unit 50 and is hermetically secured to the upstanding side walls 52 of the unit oven 50.

The reflector plate 54, which supplies radiant heat to the foodstuff also serves as the top plate of a fuel tank 76 defined by the reflector plate 54 and the lower portion of the oven unit 50.

As shown in FIGS. 5 and 6, the reflector plate 54 has an aperture 64 through which an inlet tube 66 interconnects the fuel tank 76 with a perforated burner tube 70 mounted on the reflector plate 54. A conventional metering valve assembly 68 is positioned between the inlet tube 66 and the perforated burner tube 70 and regulates the fuel flow from the fuel tank 76 through the inlet 66 and into the perforated burner tube 70.

A telescoping manual regulating means 72 is provided on the valve assembly 68 and preferably comprises a shank portion coextensive with a shaft 74 of the valve assembly 68. The manual regulating means 72 telescopes as at 72A through registering apertures 58 and 58' provided in the oven unit 50 and the base unit 46, respectively, to provide exterior regulation of the fuel flowing into the burner tube 70.

As is shown in FIGS. 2, 3 and 4, when the food 'warmer unit 34 is operable and the sidewalls 38 are extended, ventilation to the oven unit 50 is provided through port vents 56 peripherally disposed on the side walls 52 of the oven unit 50 above the reflector plate 54.

The fuel in the burner tube 70 is ignited by a means similar to that employed in a cigarette lighter and is generally indicated at 78.

The igniter assembly 78 is constructed to provide a means whereby its spark is unidirectionally emitted into the fuel escaping from the initial perforations in the burner tube 70. As, will be more fully described hereinafter, the igniter assembly is operable only when it is pivotally rotated so that it extends through registering apertures 60 and 60-respectively provided in the oven unit side wall 52 and the base unit sidewall 44.

As is illustrated in FIGS. 7 and 8, the igniter assembly preferably comprises a base plate 80 pivotally secured to the reflector plate 54 by any means such as a pin 81. An upstanding flange 82 integral with the base plate 80 has an aperture 84 provided therethrough.

An open ended, cylindrical tube 88 is aligned With the aperture 84 by a collar 95 secured to the base plate 80. The end portion of the tube '88 aligning with aperture 84 threadingly receives a thumb screw 90 with a spring 85 disposed thereon. The spring 85 urges a flint 92, which is enclosed within the tube 88, to the opposite open end of the tube 88 where a striker wheel 94 engages the flint as it is urged beyond this open end.

The striker wheel 94 is secured to a slotted arm 96 which is in turn limitedly pivotally connected as at 97 to a plunger 98 which is positioned to extend through the flange 82 and an upstanding flange 100. A washer 104 is mounted on plunger 98 and compreses a spring 102 against the flange 82 to normally urge the plunger 98 to the left as shown in FIG. 7.

To ignite the fuel in burner tube 70, the igniter assembly is first rotated counterclockwise through the registering access apertures 60 and 60' to extend outwardly for manual operation. The plunger 98 is then depressed against the force of the spring 102 causing the slotted arm 96 to move from its normal position P to its limited position P to rotate the wheel '94 against the flint 92 to generate a spark and ignite the fuel issuing from the burner tube 70.

Unidirectional emission of the sparks is promoted by a shield 124 secured to the base plate 80 as at 125 and which overlies the striker wheel 94 and the flint 92 to prevent any mishaps from occurring by errant sparks, since any such sparks will be deflected towards the burner tube 70 by the shield 124.

Registering apertures 62 and 62' disposed in the oven unit side wall 52 and the base unit side wall 44 respectively, provide access for exteriorly replacing the flint 92 whenever it is desired by removing the thumb screw 90 and the spring 85 and inserting a new flint, after which the spring 85 and the thumb screw 90 are reinstalled.

It will be readily appreciated that the metering and the ignition of the fuel which could otherwise accidentally injure the operator are operations performed exteriorly of the oven unit 50 and the base unit 46.

Referring again to FIG. 6 a grill plate 120 is removably emplaced within the oven unit 50 and rests on supports 122 which are punched out of the sidewalls 52 at their intersections and near the top of the side walls 52 as shown in FIG. 4. When the extensible side walls 38 are telescopingly vertically extended, the area within these side walls 38 and the grill plate 120 defines an oven chamber 123 within which the foodstuff to be heated is deposited atop the grill plate 120 and is thereby protected from the direct flame emanating from the burner tube 70.

To operate the food-warmer unit 34, the extensible side walls 38 are vertically telescopingly extended to define the oven chamber 123. The fuel flow regulating means 72 is then telescoped outwardly through registering apertures 58 and 58 and so rotated as to give the desired fuel flow into the :burner tube 70. The operator then pivots the igniter assembly 78 to extend the plunger 98 through the registering apertures 60 and 60', and then depresses the plunger 98 so that the resultant spark will ignite the fuel as hereinbefore described. The oven unit is now operational and the foodstufi can be heated.

When the fuel tank 76 needs to be replenished, means are provided to accomplish this, also exteriorly of the oven unit 50 and the base unit 46. As shown, a conventional spring valve means 112 is provided as an inlet into the tank 76, being secured to a wall 114 of a recess 116 provided on the side wall 52 of the oven unit 50. The recess registers with an aperture provided in the base unit side wall 44. The neck of a pressurized fuel refill bottle 118 or the like is inserted through the aperture 110 and recess 116 and engages the valve 112. The force of the fuel in the fuel supply 118 opens the valve 112 against the spring to allow the fuel to enter the fuel tank 76.

When not in use, the extensible side walls 38 are telescoped into the space intermediate the oven unit 50 and the side walls 44 of base unit 46, thus closing off registration between all the normally registering apertures preventing inadvertent operation of the valves and igniter. The lid 36 is then closed so that the entire assembly lies within the base unit 46, which can then be slidingly inserted into the storage compartment 12 of the lunchbox through its open side wall 32.

The food-warmer unit 34 can be used, as Well as stored, independently of the lunchbox container 10. The food-warmer unit can be collapsed and stored within the base unit to be transported and employed as is or carried in another container suitably adapted for the purpose.

In a less expensive model of the invention, the igniter assembly is eliminated and the fuel is ignited by inserting a lit match or the like through the apertures 58 and 58. when the oven side walls are extended.

Although I have described and shown only one embodiment of my invention, it will be apparent to one skilled in the art to which the invention pertains that various changes and modifications may be made therein without departing from the spirit of the invention as expressed by the scope of the appended claims.

I claim:

1. A portable food-warmer assembly comprising (a) a base unit including an open-top container (b) an oven unit mounted therein and including a gas fuel tank spaced from the side walls of said base unit (c) a perforated burner tube overlying said tank and connected therewith,

(d) a hot plate secured to said oven unit overlying said burner tube, and

(e) said oven unit having side walls selectively telescopically extensible into and out of the space intermediate said base unit side walls and said fuel tank.

2. The assembly as defined in claim 1 and including a lid hinged to said oven unit side walls.

3. The assembly as defined in claim 1 and including manually operable valve means for selectively admitting fuel from said tank to said burner, a side wall of said base unit having an aperture registering with an aperture in said unit and with valve means for manual access thereto.

4. The assembly as defined in claim 3 and in which the side walls of said oven unit are arranged when telescoped into said space to close registration between said apertures.

5. The assembly as defined in claim 1 and including manually operable igniter means for selectively igniting fuel issuing from perforations in said burner tube, a side Wall of said base unit having an aperture registering with an aperture in said oven unit and with said igniter means to provide manual access thereto.

6. The assembly as defined in claim 5 and in which the side walls of said oven unit are arranged when telescoped into said space to close registration between said apertures.

7. The assembly as defined in claim 1 and including valve means disposed in a recess in said tank for selectively connecting a filler valve nozzle thereto from exteriorly of said assembly, a side wall of said base unit having an aperture registering with said recess for access to said valve.

8. The assembly as defined in claim 7 and in which the side walls of said oven unit are arranged When telescoped into said space to close registration between said aperture and said recess.

9. The assembly as defined in claim 1 and including a heat reflector plate disposed between said burner tube and said tank, said burner tube having an inlet extending through said reflector plate and connected with said tank.

10. The assembly as defined in claim 1 and in which said burner tube has an end connected with said tank,

. and includes a valve means for selectively admitting fuel from the tank to said tube.

11. The assembly as defined in claim 10 and including igniter means disposed adjacent a burner tube perforation and selectively operable to ignite fuel issuing therefrom.

12. The assembly as defined in claim 11 and in which said igniter means comprises a flint and striker element arranged and operable to spark ignite fuel issuing from said burner tube.

13. The assembly as defined in claim 12 and including means for promoting unidirectional emission of a spark from said flint, said promoting means comprising a shield overlying said flint and said striker.

14. The assembly as defined in claim 12 and in which a side wall of said base unit has an aperture registering with an aperture in said oven unit, said apertures being adjacent said igniter assembly, said igniter assembly being inoperable when normally positioned within said oven unit, and in which said igniter assembly is operable only when extended through said registering access aperture.

15. A lunchbox assembly comprising (a) a container for carrying food articles (b) a base integrally constructed with the bottom of said container and having a compartment provided with an open side (c) a portable food-warmer assembly sized and adapt ed for selective storage in said compartment and removal from said open side, and (d) said food-warmer assembly comprising a base unit including an open-top container, an oven unit mounted therein and including a gas fuel tank spaced from the side walls of said base unit, a perforated burner tube overlying said tank and connected therewith, and a hot plate secured to said oven unit overlying said burner tube, and said oven unit having side Walls selectively telescopically extensible into and out of the space intermediate said base unit side walls and said fuel tank.

References Cited UNITED STATES PATENTS 761,559 5/1904 Totten et al. 126-38 899,026 9/1908 Buren 126262 2,553,101 5/1951 McKee et al. 43l-277 X OTHER REFERENCES Schmidt et al., German application No. 1,205,249, pub. Nov. 18, 1965.

CHARLES J. MYHRE, Primary Examiner US. Cl. X.R. 

